Estoy iniciando una aplicación basada en Java y Tomcat. Estoy teniendo el siguiente error.

Dec 08, 2015 12:04:00 PM org.apache.catalina.startup.SetAllPropertiesRule begin
WARNING: [SetAllPropertiesRule]{Server/Service/Connector} Setting property 'maxSpareThreads' to '50' did not find a matching property.
Dec 08, 2015 12:04:00 PM org.apache.catalina.startup.SetAllPropertiesRule begin
WARNING: [SetAllPropertiesRule]{Server/Service/Connector} Setting property 'maxSpareThreads' to '50' did not find a matching property.
Dec 08, 2015 12:04:01 PM org.apache.tomcat.util.digester.Digester endElement
WARNING:   No rules found matching 'Server/Service/Realm'.
Dec 08, 2015 12:04:01 PM org.apache.tomcat.util.digester.Digester endElement
WARNING:   No rules found matching 'Server/Service/Host'.
javax.xml.parsers.FactoryConfigurationError: Provider org.apache.xerces.jaxp.DocumentBuilderFactoryImpl not found
        at javax.xml.parsers.FactoryFinder.newInstance(FactoryFinder.java:200)
        at javax.xml.parsers.FactoryFinder.newInstance(FactoryFinder.java:152)
        at javax.xml.parsers.FactoryFinder.find(FactoryFinder.java:232)
        at javax.xml.parsers.DocumentBuilderFactory.newInstance(DocumentBuilderFactory.java:120)
        at org.apache.catalina.core.JreMemoryLeakPreventionListener.lifecycleEvent(JreMemoryLeakPreventionListener.java:431)
        at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
        at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
        at org.apache.catalina.util.LifecycleBase.setStateInternal(LifecycleBase.java:402)
        at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:99)
        at org.apache.catalina.startup.Catalina.load(Catalina.java:576)
        at org.apache.catalina.startup.Catalina.load(Catalina.java:599)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at org.apache.catalina.startup.Bootstrap.load(Bootstrap.java:310)
        at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:484)
Caused by: java.lang.ClassNotFoundException: org/apache/xerces/jaxp/DocumentBuilderFactoryImpl
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:348)
        at javax.xml.parsers.FactoryFinder.getProviderClass(FactoryFinder.java:124)
        at javax.xml.parsers.FactoryFinder.newInstance(FactoryFinder.java:188)
        ... 16 more

He revisado todo el archivo de configuración. Cualquier ventaja es apreciada.